The invention relates to a flexible protective bellows, comprising a plurality of integrally connected turns or folds with alternate ones of the turns or folds being of different configuration from that of the intervening ones.
One such form of bellows is shown in GB-A-2 031 530. In this bellows, each bellows turn or fold differs in configuration from the adjacent bellows turn or fold in that it is of a different size thereto, each of the bellows turns or folds being triangular in cross-section. A problem arises with this type of construction in that, when compressed, the straight sides of the adjacent triangular-shaped bellows turns or folds abut with each other and are in contact over relatively large surface areas, and this can cause wear. Another example of such a bellows is shown in GB-A-2 199 093. In this bellows, though, the bellows turns or folds are of greatly varying configuration along the length of the bellows, and the construction is thus complex and is suitable only for specialised applications.
The invention also relates to a flexible protective bellows, comprising a plurality of integrally connected turns or folds with each fold being integrally connected to the next fold and defining a trough between them.
Examples of such bellows are shown in GB-A-2 031 530 and GB-A-2 199 093, referred to above. Another example is shown in U.S. Pat. No. 4,702,483. A problem which arises with such bellows, however, is that excessive wear can occur due to fatigue in the material of the bellows at the troughs between adjacent bellows turns or folds. The invention aims to overcome this problem.
The invention further relates to an arrangement for securing a flexible protective bellows to a member forming at least part of a rotary mechanism to be protected by the bellows, comprising a circumferential groove in the said member for receiving a profile formed in the material of the bellows and adjacent one end thereof.
An example of such an arrangement is shown in GB-A-1 218 729. It is extremely important that the bellows be securely anchored in the groove so as to prevent any relative movement taking place which is particularly likely to occur when the material of the bellows is cold and thus relatively stiff.